Watch movement

ABSTRACT

A watch movement comprises a barrel holding a mainspring, a third wheel, and a center seconds wheel. The barrel directly drives the third wheel which in turn directly drives the center seconds wheel thereby eliminating the use of a center wheel. An automatic winding mechanism is provided, the winding mechanism comprising a rotor and a single reduction gear interposed between a pinion mounted on the rotor and a ratchet on the barrel.

United States Patent 1 Kocher et al.

451 Aug. 26, 1975 WATCH MOVEMENT [75] Inventors: Hans Kocher. Buren; Werner Haenzi, Safnern; Erwin Muff, Biel; Claude-Andre Gygaz, Evilard, all of Switzerland [73] Assignee: Societe Suisse pour llndustrie Horlogere Management Services S.A., Bienne, Switzerland [22] Filed: June 28, 1974 [21] Appl. No.: 484,260

[30] Foreign Application Priority Data July 12, 1973 United Kingdom 33297/73 52 us. Cl. 58/59; 58/82 R 511 int. Cl. G04b 33/00; G04b 5/02 [58] Field of Search 58/59, 82 R, 82 A [56] References Cited UNITED STATES PATENTS Froidevaux et al. 58/82 A 238L055 4/l96l FOREIGN PATENTS OR APPLICATIONS 71,081 lO/l9l4 Switzerland"; 58/59 1,742 3/l902 Switzerland Primary Examiner- George H. Miller, Jr. Attorney, Agent, or Firm-Griffin, Branigan and Butler [5 7] ABSTRACT A watch movement comprises a barrel holding a mainspring, a third wheel, and a center seconds wheel. The barrel directly drives the third wheel which in turn directly drives the center seconds wheel thereby eliminating the use of a center wheel. An automatic winding mechanism is provided the winding mechanism comprising a rotor and a singlereduction gear interposed between a pinion mounted on the rotor and a ratchet on the barrel.

5 Claims, 2 Drawing Figures I WATCH MOVEMENT The present invention providesa new simplified version of a watch movement which nevertheless lends itself to realization as a high quality time-piece.

To this effect, the watch movement is provided with most of the parts generally found in present day watches, but in the present case the so-called center wheel, i.e. grande moyenne, has been eliminated. Thus instead of the power from the main spring being transmitted via the barrel through the usual wheel train to the escapement, the power now goes directly to the third wheel, i.e. petite moyenne. The consequence of this is that by elimination of the center wheel the main spring will unwind much faster than in watches of usual construction. In the present instance the unwinding rate is about double the usual rate. Owing to this elimination of the center wheel, the forces to be transmitted are reduced and accordingly the main spring can be made of lighter material.

The fact that the watch as now conceived would normally run down in about half the usual time would seem to present certain disadvantages. However, as a further feature we provide an automatic winding arrangement and it is seen that with this winding arrangement the running down time of the main spring is much less important. In most automatic watches the reserve time available is from 40-50 hours assuming the main spring to be completely wound at the time the wearer removes the watch. It will be seen that as long as the wearer does not put aside a watch according to the present invention for more than about a day it will still continue to run. The fact that the main spring is substantially lighter than in normal watches of this caliber means that the self-winding mechanism can be appreciably simplified through the elimination of a considerable portion of the step down gearing or lever arrangement normally necessary between the self-winding rotor and the barrel ratchet. Other advantages stemming from the invention are the fact that, in view of the smaller forces involved, certain parts may be made of synthetic materials, such as injected plastics, without loss of quality.

Accordingly, the invention provides a watch movement wherein the barrel directly drives the third wheel which in turn directly drives the center seconds wheel. As a further feature the movement provides an automatic winding mechanism comprising a rotor and a single reduction gear between the rotor pinion and the barrel ratchet.

For a better understanding of the invention reference will now be made to the accompanying drawings in which:

FIG. 1 is a partial sectional view showing the going train and the motion work of a watch movement according to the invention; and,

FIG. 2 is a cross-sectional view showing the basic parts in the automatic winding train.

In FIG. 1, l-] is the barrel containing the main spring. The gear ring on the barrel engages with pinion l-3 which is integral with axle 1-2. Fixed solidly to shaft 1-2 is the third wheel, i.e. petite moyenne, 14. Third wheel l-4 meshes with pinion l-5 which is fixed to fourth wheel 1-8. Wheel 1-8 in turn meshes with the escape pinion l-9.

Fourth wheel 1-8 and its pinion 1-5 are in the center of the movement and coaxial with the axle l-6 of the center seconds hand 1-7. Axle l-6 is fixed to the fourth wheel I-8 and its pinion l-S so as to be driven thereby.

Barrel ll to pinion l-3: l :l

In the motion work it will be noted that fixed to the shaft l-2 is the pinion 1-10 which drives a minute wheel 1-1 1. Minute wheel l-l-l is friction fitted to cannon pinion 1-12. Cannon pinion 1-12 of course has fixed thereto a minute hand 1-13, but at the same time is arranged and adapted to drive the hour cannon l-l5 and its hour hand l-16 via wheel l-l4.

Although different designers may choose to arrange specific gear ratios in a different manner it has been found by way of example that in the going train the following gear ratios may be used:

Third wheel l-4 to pinion l-S: Fourth wheel l-8 to escape pinion 1-9:

From the foregoing it will be seen that with the second handmaking I complete revolution per minute and with the standard 15 tooth escapement the balance wheel frequency will be 21,600 beats per hour. The

third wheel will rotate at the rate of 12 times per hour and the barrel will make 1 revolution in 2.4 hours, which as mentioned above is approximately twice the normal speed.

The working out of the other ratios will present no problem to anyone skilled in the art.

FIG. 2 shows a simplified automatic winding train wherein 2-1 is the barrel corresponding to 1-1 of FIG. 1 and 2-2 is the barrel ratchet. The rotor is represented by 2-3 and in the present arrangement may comprise a free running eccentric weighted lever pivoted in the center of the movement. Rotor center hub 2-11 has a pinion 2-4 friction fitted thereto. A leaf spring 2-10 is fixed along one edge of the rotor and arranged to engage with the teeth of pinion 2-4 in a manner such that when the rotor 2-3 turns in one sense the leaf spring 2-10 drives pinion 24 while in the other sense the spring rides over the teeth of pinion 2-4. Pinion 2-4 drives gear 2-5. Gear 2-5 is fixed to pinion 2-6 and pinion 2-6 meshes with the barrel ratchet 2-2.

Winding stem 2-7 drives a crown pinion 2-8 that normally meshes with a winding wheel 2-9. Wheel 2-9 engages pinion 2-6 whereby the movement may be manually wound.

In view of the spring arrangement 2-10 the movement is wound when the rotor turns in one direction. At the same time, manual windings will not cause the rotor to turn since in this case pinion 2-4 will be rotated in its free-running sense. In view of the much lighter main spring which can be used in this movement, a single reducer has thus been found adequate and this, in addition to simplifying the mechanism, enables the use of lighter materials including injected plastics.

What we claim is:

l. A watch movement comprising a barrel holding a mainspring, a third wheel and a center seconds wheel, wherein the barrel directly drives the third wheel which in turn directly drives the center seconds wheel thereby eliminating the use of a center wheel.

2. A watch movement as in claim 1 including an automatic winding mechanism, said mechanism comprising a rotor and a single reduction gear interposed between a pinion mounted on said rotor and a ratchet on the barrel.

3. A watch movement as in claim 1 wherein portions of the mechanism are made from injected plastic materials.

I 4. A watch movement as in claim 1 wherein the gear 5. A watch movement as in claim 3 wherein portions ratios are chosen such that with use of a balance wheel of the mechanism are made from injected plastic matehaving a frequency of 21.600 beats per hour, the barrel rials.

will make one revolution in 2.4 hours.

273 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,901,019 Dated August 26, 1975 v fls) Hans Kocher, Werner Haenzi, Erwin Muff,

& Claude-Andre Gygaz It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2., line 55, after "movement" insert including an automatic winding mechanism and Column 2, line 60 cancel "including an auto" Column 2, line 61, cancel "matic winding mechanism," and insert wherein Column 2, line 61, after "said" insert automatic winding Column 2 line 61,- cancel "comprising" and insert comprises Signcd and Scalzd this fourth I D ay of November 1975 ESEAM Arrest:

L mm; c. msou c. mnsmu. DANN J Arresting Officer Commissioner nfPamm and Trademark:

P0-1050 I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3,901,019 Dated August 26, 1975 Inv nt Hans Kocher, Werner Haenzi, Erwin Muff, & Claude-Andre Gygaz It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2 line- 55 after "movement" insert including an automatic winding mechanism.

. and

Column 2, line 60 cancel "including an auto-" Column 2, line 61, cancel "matic winding mechanism," and insert wherein Column 2, line 61, after "said" insert automatic winding 0 Column 2, line 61, cancel "comprising" and insert comprises A Signed and Scaled this fourth Day of November1975 MEAN Arrest:

L RUTH C. MASON C. MARSHALL DAN" J 8 ffi (ommissiuner ujParems and Trademarks 

1. A watch movement comprising a barrel holding a mainspring, a third wheel and a center seconds wheel, wherein the barrel directly drives the third wheel which in turn directly drives the center seconds wheel thereby eliminating the use of a center wheel.
 2. A watch movement as in claim 1 including an automatic winding mechanism, said mechanism comprising a rotor and a single reduction gear interposed between a pinion mounted on said rotor and a ratchet on the barrel.
 3. A watch movement as in claim 1 wherein portions of the mechanism are made from injected plastic materials.
 4. A watch movement as in claim 1 wherein the gear ratios are chosen such that with use of a balance wheel having a frequency of 21,600 beats per hour, the barrel will make one revolution in 2.4 hours.
 5. A watch movement as in claim 3 wherein portions of the mechanism are mAde from injected plastic materials. 